First mass vaccination with single-dose oral cholera vaccine in response to an outbreak in Juba, South Sudan Lucy Anne Parker, John Rumunu, Christine Jamet, Yona Kenyi, Richard Laku, Lul Deng, Bior K Bior, Michael Lasuba, Joseph F Wamala, Allan M Mpairwe, Fisseha Tadesse, Augusto Llosa, Sandra Cohuet, Marie-Laure Quilici, David A Sack, Iza Ciglenecki, Francesco Grandesso, Francisco J Luquero, Andrew S Azman. Lucy A Parker - MSF - First mass vaccination with single-dose oral cholera vaccine in response to an outbreak in Juba, South Sudan

Global cholera burden continues to be high Introduction Global cholera burden continues to be high Source: WHO Lucy A Parker - MSF - First mass vaccination with single-dose oral cholera vaccine in response to an outbreak in Juba, South Sudan

Context: South Sudan Independence from Sudan in July, 2011 Civil war broke out in 2013 Nearly 2 million internally displaced Over 7,500 medically attended cholera cases in 2014 and 2015 Image : https://www.cia.gov/library/publications/the-world-factbook/geos/od.html Lucy A Parker - MSF - First mass vaccination with single-dose oral cholera vaccine in response to an outbreak in Juba, South Sudan

Oral Cholera Vaccine 3 vaccines prequalified by WHO OCV Shanchol® (2011) Semi-affordable (<2USD/vial) 2 doses proven feasible and effective Preventative Reactive (response to outbreaks) Vaccine shortage is a major obstacle Photo: Jacob Kuehn, MSF Lucy A Parker - MSF - First mass vaccination with single-dose oral cholera vaccine in response to an outbreak in Juba, South Sudan

Cholera Timeline, Juba, 2015 Lucy A Parker - MSF - First mass vaccination with single-dose oral cholera vaccine in response to an outbreak in Juba, South Sudan

Rational: Single-dose OCV Juba Juba appears to serve as a hub of transmission for the country Limited number of vaccines available Single dose of OCV has potential to save more lives Herd protection, immunological studies, preliminary trial data, mathematical modelling Lucy A Parker - MSF - First mass vaccination with single-dose oral cholera vaccine in response to an outbreak in Juba, South Sudan

OCV campaign (31 July-5 Aug 2015) Single-dose Shanchol® offered to individuals aged ≥1 year targeted areas of Juba high risk groups Large fixed sites and mobile teams Limited social mobilisation Vaccination coverage survey using spatial random sampling Lucy A Parker - MSF - First mass vaccination with single-dose oral cholera vaccine in response to an outbreak in Juba, South Sudan

Aim To evaluate the feasibility, coverage, and vaccine effectiveness of this first ever use of single-dose OCV as an outbreak response Lucy A Parker - MSF - First mass vaccination with single-dose oral cholera vaccine in response to an outbreak in Juba, South Sudan

Methods: Case-cohort study Suspected cholera cases confirmed through multiple diagnostic tests Cohort of a spatially representative sample from across Juba Vaccination status ascertained by interview and inspection of vaccination card Unadjusted and adjusted vaccine effectiveness estimates were derived from proportional hazard regression models. Ethics: Approved by the John Hopkins Bloomberg School of Public Health IRB and the Ethical Committee of the Ministry of Health, Republic of South Sudan. Lucy A Parker - MSF - First mass vaccination with single-dose oral cholera vaccine in response to an outbreak in Juba, South Sudan

Results: Feasibility ~143,000 persons ~ 22,000 persons main campaign 31 July-5 Aug 2015 ~ 22,000 persons comprehensive package immediate neighbourhoods of suspected cases Vaccine coverage in targeted areas 68.8% (95%CI: 63.9 – 73.6%) Photo: Jacob Kuehn, MSF Lucy A Parker - MSF - First mass vaccination with single-dose oral cholera vaccine in response to an outbreak in Juba, South Sudan

Results: Vaccine effectiveness (VE) 87 suspected cases; 32 classified as cholera positive 898 cohort members; 858 successfully followed No cohort members sought care for clinical cholera Direct and Indirect protection offered by the vaccine: Unadjusted single-dose VE: 79.5% (95%CI 59.9-100) Adjusted single-dose VE: 89.6% (95%CI 75.3-100.0) Lucy A Parker - MSF - First mass vaccination with single-dose oral cholera vaccine in response to an outbreak in Juba, South Sudan

Limitations Observational study in challenging field conditions Confirmed cholera cases in Juba ceased within 2-weeks of vaccination campaign limited sample size, high uncertainty Nearly 50% of participants did not have their vaccination cards Potential for natural immunity in the study population due to cholera history in Juba Lucy A Parker - MSF - First mass vaccination with single-dose oral cholera vaccine in response to an outbreak in Juba, South Sudan

Discussion Important evidence for deciding on vaccine strategy in light of limited OVC supply A single-dose of OCV offers high levels of protection against severe cholera both direct and indirect herd protection A single dose also logistically simpler and less expensive to deploy in emergencies Lucy A Parker - MSF - First mass vaccination with single-dose oral cholera vaccine in response to an outbreak in Juba, South Sudan

Conclusions Until sufficient doses of OCV are available, flexible alternative vaccination strategies are needed including highly targeted vaccination campaigns and single-dose regimens. Our results from an outbreak in an urban context show that both are feasible and effective. Lucy A Parker - MSF - First mass vaccination with single-dose oral cholera vaccine in response to an outbreak in Juba, South Sudan

MSF-OCG Iza Ciglenecki Lameck Ontweka OCG Cell 1 (Christine, Barbara, Javier) Jean-Clement Cabrol Micaela Serafini Florent Uzzeni Epicentre Paris Francisco Luquero (Co-PI) Fisseha Tadesse Francesco Grandesso Augusto Llosa Sandra Cohuet Anne-Laure Page Thank you! South Sudan Ministry of Health John Rumunu Richard Laku Thomas Ujjiga Yona Kenyi Lul Deng Bior Bior Michael Lasuba Abiem Bona Institute Pasteur, Paris Marie-Laure Quilici WHO Juba, South Sudan Alan Mpwaire Joseph Wamala Johns Hopkins University Andrew Azman (Co-PI) David Sack Justin Lessler Amanda Debes Lucy A Parker - MSF - First mass vaccination with single-dose oral cholera vaccine in response to an outbreak in Juba, South Sudan